Bacteria (Kingdom): Additional to the
previous taxonomic information given in the bacteria domain section,
all organisms found in the bacteria kingdom are unicellular and
consist of mainly "free-living" bacteria.

Gamma proteobacteria:
Within this large subgroup lies the Gram-negative bacteria
that are capable of undergoing fermentation and live under aerobic
conditions.

(Legionella pneumophila, is another pathogenic bacterium in
this group that is knownas the cause of
Legionnaire's Disease.)

Xanthomonadales:
Within this order there are no formation of endospores.
Organisms are classified as obligate aerobes. They are more
specifically identified as Gram-negative straight rods.

Xanthomonadacae: Environmental
organisms found in moist soil areas. Plant pathogenic
bacterial species, and one known human pathogen is located here.

Xanthomonas: Organisms
within this genus typically are catalase positive; oxidase negative.
Colonies are typically yellow pigmented. Some are motile by a
single polar flagellum. Gram-negative single rods, mostly
single or in pairs. Do not have resting stages within life
cycle.

Xanthomonas campestris:
A Gram-negative rod shaped plant pathogenic bacteria. Targets
specifically plants within the crucifer family. Its associated
disease is commonly known as the black rot, which is an systemic
disease which eventually leads to necrosis. The protective
coating of the bacterium is also used to produce the food additive
xanthan gum.

The more meaningful name to remember Xanthomonas campestris (Xcc)
for is either is plant pathogen name, black rot or by the food
additive product, xanthan gum. These both have a logical
reasoning behind their meaning. The
black rot refers to Xcc's parasitic relationship with
crucifer plants. Also xanthan gum
naming scheme comes from the fermentation process of the outer
coating of Xcc that produces this food additive.

The above phylogenetic tree, located next to Xanthomonas
campestris' complete taxonomic classification, goes into detail
of the morphological levels that associate with Xcc.
However, that phylogenetic tree only represents to the specific
phylum that Xcc is associated with, so a more detailed
morphological phylogenetic tree is represented below of Xcc:

As seen, Xanthomonas campestris
has many close relatives that also participate in this destructive
parasitic lifestyle. Even though other organisms participate
in this type of lifestyle, it is important to understand what
Xcc has as a specific location and
habitat that will benefit the pathogenic bacteria's life cycle.